Axial load resistant key switch
AssigneeITT Composants et Instruments
InventorJean-Claude Lefebvre
Life of this patent
Estimating the term…
Abstract
A short travel key switch comprising an electrically insulating base having a bottom and a cylindrical lateral wall defining a cavity closed by a cap. A central contact and a lateral contact are mounted on the bottom. The periphery of a switching element received in the cavity is in electrical contact with the lateral contact. The element is elastically yieldable to establish an electrical connection between the two contacts in response to an axial load exerted on its convex face by the facing portion of an actuator. The central contact is mounted flush with a plane central portion of the bottom. The facing portion of the actuator which engages the central contact is flat.
Claims6
In a key switch comprising an electrically insulating base having a bottom and an upstanding lateral wall defining a cavity closed by a cap, a central contact and a lateral contact mounted on said bottom, a dome-shaped switching element mounted in said cavity over said contacts, the periphery of said element being in electrical contact with said lateral contact, said element being elastically yieldable to establish an electrical connection between said contacts in response to an axial load exerted on the convex face of said element, an actuator for exerting said axial load, said actuator having a facing portion disposed over said element and a stem passing through a central hole in said cap, the improvement which comprises:
- said bottom of said base having a plane central portion facing said switching element;
- said central contact comprising an upstanding projection having an essentially flat contacting surface facing said switching element, said projection being embedded in said base with said flat contacting surface being flush with said plane central portion;
- and
- said facing portion of said actuator being a flat face generally parallel to said flat contacting surface.
A key switch comprising:
- an electrically insulating base having a bottom provided with a plane central portion;
- a central contact and a lateral contact mounted on said bottom;
- said central contact comprising an upstanding projection having an essentially flat contacting surface, said projection being embedded in said base with said flat contacting surface being flush with said plane central portion;
- a dome-shaped switching element mounted over said contacts, the periphery of said element being in electrical contact with said lateral contact;
- said element being elastically yieldable to establish an electrical connection between said contacts in response to an axial load exerted on the convex face of said element;
- and
- an actuator for exerting said axial load, said actuator having a flat face disposed over said element above said central contact and being generally parallel to said flat contacting surface.
Dependencies are inferred from the claim text.